Abstract: In this paper, the method of estimating parameters for three-parameter Weibull distribution by the maximum likelihood method is provided. By postulating a value of the location reference λ3, we substitude the maximumlikelihood duality equations contained only two parameters except for λ3 in three-parameter Weibull model instead of maximum likelihood equations for three-parameter, the convergence field of Newton iterative procedure can be expanded, its convergence velocity can be quickened and the efficiency of parameter estimators is higher than the parameter estimators by the method of moment.